Anti-diabetic drug Metformin may decrease cancer risk in non-smokers

For the first time, researchers were able to find a direct link between an anti-diabetic drug and lung cancer. Prolonged use of an anti-diabetic drug, metformin is related to lowering of lung cancer risk in non-smokers while it increases the chances of the same in smokers, say researchers from Kaiser Permanente Division of Research in Oakland, California.

“Our results suggest that risk might differ by smoking history, with metformin decreasing risk among non-smokers and increasing risk among current smokers,” said lead researcher Lori Sakoda.

For the study, scientists observed nearly 47,351 diabetic patients including 25570 men and 21781 women, for almost 15 years. All the participants were older than 40 years and had participated in a health related survey between 1994 and 1996. In a time span of 15 years, researchers diagnosed 747 patients with lung cancer. After analysing the data, they found that metformin played a significant role in causing lung cancer in both, smokers and non-smokers.

Prolonged use of Metformin was related to the reduction of 43% chances of lung cancer in diabetic patients who had never smoked in the past. With prolonged use, the effect seems to get more pronounce. It was also noticed that use of metformin for more than five years was associated with 31 percent decrease in the risk of adenocarcinoma, most common type of lung cancer found in non-smokers. However, the drug also has some downsides; its prolonged use was associated with 82% increase in the risk of small-cell carcinoma, commonly found in smokers.

Apart from levelling lung cancer risk, the drug can play a significant role in decreasing cardiovascular diseases. Researchers say it can reverse the age-old belief of higher heart attack chances associated with HIV. However, more detailed study is required to confirm the findings.